Txt 'creaking' Clutch

[seavoyage]

1995 JT35. Noticed that the clutch lever 'creeks' like a cable clutch engaging a spring and releases clutch on the final 10mm of release.Often the lever sticks in position right before the last 10mm of release, then suddenly releases.

I use 75W transmission oil on this motor and not theDEXRON III ATF (on my Pro). No issues shifting, but when slipping the clutch, it isn't gradual - the clutch doesn't engagement until the last 10mm then it's a light switch - kind of like dropping the clutch but not as dramatic.

When the clutch lever is pulled in (engaged) - no creeping forward. It's fine on tick-over.

I thought it may be the pivot bolt was too tight at the clutch lever at first or a lack of lubrication on the plastic bushings on the AJP levers where catching. - but it's seemed ok.

Any ideas?

[lineaway]

Probably should rebuild (which is fairly cheap) the master cylinder.

[thats_a_five]

Time to rebuild the master cylinder and bleed the system. The seal on the master cylinder does such a good job of keeping the oil inside the system that dirt and rust collect behind the seal. This causes the piston to not move smoothly and usually not return to the fully retracted position. Repair kits are readily available for about US$20. Be sure to clean the bore in the cylinder and the groove for the retaining ring well.

[seavoyage]

Thanks for the prompt response. AJP Master Cylinder rebuild kit on order.

Edited April 15, 2013 by seavoyage

[seavoyage]

Update: Flushed the clutch and replaced clutch hydraulic fluid . Worked the master cylinder piston and backed out the adjustment screw. Voila! Works just fine. I guess I'm returning the Master Cylinder Rebuild kit. BTW - Adrian (LewisportUSA) thought that it was a low probability that the root cause of the creaking would be the master cylinder which wasn't leaking, and more [probable it was the clutch pack... so I took a look, everything looked fine and the stack measured within specs.

[jse]

Update: Flushed the clutch and replaced clutch hydraulic fluid . Worked the master cylinder piston and backed out the adjustment screw. Voila! Works just fine. I guess I'm returning the Master Cylinder Rebuild kit. BTW - Adrian (LewisportUSA) thought that it was a low probability that the root cause of the creaking would be the master cylinder which wasn't leaking, and more [probable it was the clutch pack... so I took a look, everything looked fine and the stack measured within specs.

You might want to hang on to the kit. Some of the early models had the piston return spring break when worn. It's always good to have a clutch M/C kit in your parts box, the clutches get a real workout in Trials and it might save you a day of riding sometime.

Jon

[bogwheeler]

Sounds like the same problem I had with my 07 Sherco. Went the same route starting with a fluid flush. I removed the slave cylinder and placed a heavy spring against the piston held in place with a c-clamp. I got smooth lever action so I put the slave cylinder back on, same problem, but not as bad. Next I removed the clutch assembly and hand filed all the little grooves off the clutch basket fingers where the clutch plate tabs ride. Then, with small strips of 120 grit emery cloth, using a back and forth action (like buffing your Sunday dress shoes) to polish off the mating rough edges of the tabs on the clutch plates. (I guess this is what they call the Beta Clutch Fix.) This little rework project is not hard to do, but takes a good couple hours just for the sanding and filing alone. I reassembled, filled trans with 75W Maxima MTL. Now the clutch works as good or better than It ever did. A very smooth engagement. No More Creaking!